Neuroscience, Underwater

[media-credit name=”Natalie Wolff” align=”alignnone” width=”300″][/media-credit]On the night of June 23rd, neuroscientist Vincent Pieribone knelt on the bottom of the ocean, chiseling off a shard of coral. He was an hour off the coast of Kennedy Island, a deserted island in the South Pacific. The ocean floor was pitch-black, but he knew that all around him were the ghostly ruins of planes and warships sunk during World War II. As if these twisted, hulking metal shapes weren’t creepy enough, the water was also teeming with an endless catalog of things that could kill him.

“There are serious sharks there — blacktip open ocean sharks that will take a bite off you,” he said. “But in diving, it’s the little things that get you.” Little things like the box jellyfish. Pieribone wasn’t worried about them, because if he were to get stung, he’d be dead too fast to do anything anyway. But he was worried about the cone shells, which inject venomous harpoons into their prey as they scoot along the ocean floor; he was worried about blue-ringed octopi, which come out at night to hunt with their own heart-stopping venom; he was worried about his motorized canoe being ravaged by a sudden squall. And if he were to get stung, or scraped by the infection-laden coral, or even hit by the boat’s propeller, he would have to spend over three hours in two different boats to get to the capital of the Solomon Islands, where the hospital, run-down and flanked by open sewers, seems almost as risky as the seafloor. “It was absolutely petrifying,” he says.

The reason Pieribone was braving all these dangers was the sliver of coral he was chipping off the reef. It contained a gene that makes the animal shine a brilliant fluorescent red. Pieribone wanted to borrow that gene and inject it into the brain. He was hoping to create a microscopic light show in which every flash is caused by activity in a single neuron, allowing computers to read a person’s intentions flickering across the brain. For people with paralysis, this gene could mean being able to control a robot with their minds, thereby regaining some of their independence.

Remedying paralysis through nocturnal scuba-diving is hardly the norm for neuroscientists. They are creatures of the lab, where the only kinds of fauna they have to worry about are the fruit flies they experiment on and the grad students they teach. For most of the year, this is true of Pieribone as well. He teaches neurophysiology at the Yale School of Medicine, and examines fruit fly brains at The John B. Pierce Laboratory, a Yale-affiliated research institute.

Like plenty of his colleagues, Pieribone uses undersea material in his lab — his fly brains are injected with a jellyfish gene which allows him to see how chains of neurons interact. But unlike other neuroscientists, he sees underwater life as more than just a source for the genetic tools necessary for lab work. In fact, his concern for coral reefs rivals his concern for the human brain. Both of these interests have deep roots in Pieribone’s childhood, and it is only now, after decades of neuroscience research, that he is getting to splice them together.

When I meet Pieribone in his lab, he speaks in loops and digressions, taking information-packed detours. To arrive at how dangerous night-diving is, he goes by way of JFK’s 1943 boat crash; to explain the funding of scientific research, he describes the bizarre experiments performed by the U.S. military. He is 48, but has the charming intensity of a kid. He even looks boyish, with a round face, button nose and unruly hair. So it isn’t hard to imagine him as a kid, despite his foul mouth and five o’clock shadow.

Pieribone was a diver before he even thought of being a neuroscientist: as a kid growing up in Titusville, Fla., he spent his free time skin diving and snorkeling with his brother. “I didn’t legally dive until I was in college,” he says. “You need a license, but when we were young you didn’t, so we’d just occasionally bring down a tank. Nobody cared.” He remembers a holiday in the Florida Keys when the coral was as bright as a Matisse, the pinks and reds still pristine.

Then, during his adolescence, his focus was diverted from coral reefs to neurological diseases when his father was diagnosed with multiple sclerosis. Such a diagnosis would be devastating for anyone — there is no known cure for MS — but for Pieribone’s father, who had struggled to become a chiropractor, the disease signaled the end of a dream he’d spent his whole life trying to realize.

“When he was a kid, he had polio and lost a leg,” Pieribone says. “That was bad enough.” But the background from which he came made Pieribone’s father’s trajectory even more difficult. His parents were first-generation Italian farmers; they believed that if your father worked in the fields, you should too. Even when he lost a leg, diminishing his prospects on the farm, his family still didn’t want him going to college. He put himself through chiropractor school and set up a practice anyway. The job was hard enough with only one leg — every day, he was reshaping someone’s spinal cord through a series of quick jerks and prods and thrusts. With the tremors and weakness that characterize MS, performing a chiropractic adjustment soon became impossible. “It infuriated me,” Pieribone says of his father’s illness. “I tried to take that anger and turn it into something useful. Otherwise it would just eat you up.”

He began to read everything he could find about MS. So little was known about MS that, as a high school senior, he was able to digest all the scientific literature there was on the disease. He ended up phoning a researcher at the Albert Einstein College of Medicine in New York, and was disgusted to find that the professor didn’t know much more than he did.

Even as he buried himself in MS articles, Pieribone kept diving. At that point, the reefs were disintegrating almost as fast as his father’s ability to move. In 1982, when Pieribone went off to New York University to pursue his interest in neuroscience, both his father and the reefs took a turn for the worse. His father became depressed, which broke apart his marriage to Pieribone’s mother. And Pieribone could hardly recognize the coral reefs he’d explored while he was growing up. “There’s algae covering the reefs, this matted algae that grows when there’s too much human feces in the water, too much manure. It’s a dead zone.”

His father’s situation was becoming even more bleak: he had moved to Coler Memorial Hospital on Roosevelt Island, which sits in the East River between Manhattan and Queens. “It was a city hospital for people who couldn’t walk and who had no money,” Pieribone says. “After years of different inpatient hospitals he paid for, he ran out of money and ended up there. The whole island was pretty scary back then. Mostly deserted. There were only hospitals.”

Pieribone visited his father on Roosevelt Island over a five-year period until his father’s death. He can’t remember the year: “I’ve blocked it out,” he says. What he does remember is the anger that flared up. “My father’s death didn’t need to happen,” he says. He believes diseases like MS would be cured if society cared enough to invest more money in research. “It’s insanity that sports and that kind of bullshit gets more money than research.”

His anger also extends to the disappearance of coral reefs, which are not only fabulous in themselves, but also provide food and shelter for innumerable other species. “You burn a Library of Congress every week, because you take all these genetic sequences that took millions of years to perfect, and you kill that history,” he says. “And there’s no fucking interest in it. If it’s not a polar bear or a penguin, nobody wants to hear about it.”

In December 1997, after years of diverting this double-headed anger into his work in other people’s labs as a graduate student and postdoc, Pieribone was offered a job as primary investigator at The John B. Pierce Laboratory. He now had his own lab, which would soon allow him to connect diving with his neuroscience career, showing just how disastrous the disappearance of coral reefs could be to patients with neurological diseases.

To explain this connection, Pieribone took me to see his lab, an underground mess of computers and wires and microscopes. Carved out of the towers of equipment is a cramped space where you can electronically navigate the microscopic tip of a needle-like pipette into a fruit-fly neuron. And when Pieribone flicks on one of the computer screens, a tree-like neuron appears, glowing the otherworldly green of a creature out of Star Wars.

Pieribone made that brain cell glow by injecting it with a jellyfish protein. Under normal circumstances, that green fluorescent protein (GFP) is simply used to “tag” cells: once a cell is glowing green, you can easily follow its path through the body. Pieribone, on the other hand, is using the GFP to see which brain cells are responsible for what. He has fiddled with the protein’s genetic code so that the fluorescence flickers every time this neuron communicates with its neighbors. The language neurons use is composed of little jolts of electricity. “Essentially, we’re translating their electrical language into a visual report,” Pieribone says.

Right now, to see which exact neurons are communicating to accomplish a certain task, a neuroscientist would have to insert electrode wires into the neuron. The task isn’t just finicky — it’s also untenable, because scar tissue begins to engulf the wire. “For a few months, maybe even a year, you are able to record cells,” Pieribone says. “But over time, the recordings get really bad, because the brain rejects the foreign body.”

This problem would be avoided with Pieribone’s modified GFP. He and his Ph.D. student Jelena Platisa are now testing their sensor against electrodes, and their results look promising. Pieribone switches on another computer screen to show me, and up pop two zigzagging lines. One represents the electrical signals emerging from the fruit-fly neuron as read by the electrode, the other the intensity of the cell’s fluorescence as read by a specially designed camera.

Every peak and valley of the electrode zigzag is echoed in the GFP zigzag, indicating that that the GFP is doing exactly what Pieribone wants: it is flickering every time the neuron says something to its neighbor.

The accuracy of the sensor’s measurements places it among the most sensitive brain imaging techniques neuroscientists have. For example, fMRI allows scientists to see which general region of the brain is functioning — we’re talking millions of neurons at once — while this protein can show us the function of a single neuron at a time. This detailed level of detection means that scientists could see exactly which chain of neurons is responsible for which actions.

The implications of Pieribone’s creation could be huge. Imagine a patient who has lost the ability to move. If this sensor were injected into that patient’s brain, a computer could actually read the patient’s intentions as they flicker from one neuron to the next. That computer could then transmit the patient’s intentions to a robot, which could accomplish the movement for the patient. While scientists would have to start with simpler movements, Pieribone hopes that in a few decades a computer could differentiate between the neurons involved in accomplishing near-identical tasks — spreading butter rather than scooping it out of the dish, moving a pen to write “dear” instead of “dare” — and that the robot would be able to accomplish the exact task the patient had envisioned. If you haven’t moved since you were in a car crash, this nifty bit of biotechnology could change your life.

Pieribone is quick to point out that this sensor isn’t perfect. The tissues in our brains produce a faint green fluorescence that can interfere with the jellyfish’s fluorescence, the way stars can be lost from sight even on a street with a single streetlamp. Red fluorescence would work better: it is not only easily distinguishable from our brains’ green glow, but is also safer and can reach neurons buried deeper within our skulls. It was this image of a red fluorescent protein lighting up our brains that made Pieribone start thinking about diving at night.

In 2002, Pieribone first went diving in the South Pacific for bright red corals. But the decline of coral reefs — and underwater life in general — added an urgency to his mission. The jellyfish from which the green fluorescence was extracted is no longer seen in its native Puget Sound. “The year after it was cloned, it disappeared,” Pieribone says. He is worried the same thing will happen with other organisms before scientists get around to cloning them.

“We’re wiping all these animals off the face of the earth as fast as we possibly can. What do I do about it? I’m nothing, I’m a neuroscientist,” he says. “Nobody would give us money.” So he finagled his first trip to the South Pacific through EarthWatch, an organization that funds research by having eco-tourists pay to come along for the ride.

The papers Pieribone wrote about those first dives led to funding for more dives, including this summer’s adventure in the Solomon Islands. His team brought back hundreds of specimens whose DNA is now being combed for useful traits.

His mission is partly political — he’s still angry that people care more about football than about research, and wants to capture their imagination through swashbuckling science. To that end, he has co-written a book about underwater fluorescence and blogged for The New York Times.

Despite his anger, he’s never lost the awe he experienced as a kid in Florida. In fact, it has only increased as he has discovered the wonders of nighttime fluorescence. “The colors are like an acid trip, some crazy velvet painting from the ’60s,” he says. “As a scientist, the things you see are so amazing you lose yourself, you forget what air you have, you forget where you are, how far you’ve gone.” And I can see that I’ve lost Pieribone. He’s no longer sitting across from me in a café a few blocks from his lab. He’s underwater, kneeling on the sand, staring wide-eyed at a glowing piece of coral.